Cleaner silencer structure



March 5, 1957 J. D. KARN ET AL CLEANER SILENCER STRUCTURE 2 Sheets-Sheet l Filed Sept. 27, 1954 ATTORNEY March 5, 1957 D, KARN TAL 2,783,855

CLEANER SILENCER STRUCTURE Filed Sept. 27, 1954 2 Sheets-Sheet 2 INVENTORS N 1 i :A OrRNEY United States Patent() CLEANER SILENCER STRUCTURE James D. Kam, Flint, John D. McMichael, Swartz Creek, and Wesley W. McMullen, Flint, Mich., assignors to General Motors Corporation, Detroit, Mieli., a corporation of Delaware Application September 27, 1954, Serial No. 458,306

8 Claims. (Cl. 183-44) This invention relates to air cleaner and silencer units for use with engines and other devices having air induction means and more particularly to a unitary cleaner and silencer structure for automotive and other uses.

Air cleaners and silencers are generally made up as separate elements which are later coupled together to form a cleaner silencer assembly. It has been found, however, that in assembling such extraneous factors are introduced which may adversely affect the attenuation of sounds within the silencer. Such factors include the coupling of the separate elements and the necessity of au adequate acoustical seal therebetween.

It has been found that the most efiicient cleaner silencer assembly is a unitary construction wherein necessary acoustical impedance, capacitance, and other factors may be designed into the silencer with direct relation to a specific cleaner. it is further found that a cooperative relation of walls and surfaces between elements may be provided which presents great savings in materials, in space, and in man-hours otherwise necessary in the assembly and adjustment of separate elements.

It is now proposed to provide an air cleaner silencer structure similar to that of copending application S. N. 392,338 entitled Cleaner Silencer Unit and tiled November 16, 1953, in the name of Wesley W. McMullen. The proposed cleaner silencer is inexpensive to make in that a relatively small number of parts are used, most of which are sheet metal stampings. It is proposed to provide a unitary cleaner silencer arrangement which occupies a limited amount of space and which includes adequate internal chamber space to provide for an acoustic capacitance arrangement eliminating annoying high frequency noises. It is further proposed to provide adequate acoustical impedance means within the limited space available to attain sutlicient sound attenuation.

In the drawings:

Figure 1 is a cross-sectional side elevational view of a unitary cleaner silencer structure embracing the principles of the invention taken in the plane of line 1-1 of Figure 2 looking in the direction of the arrows thereon.

Figure 2 is an upper plane View of the proposed cleaner silencer with parts broken away to better illustrate the internal structure thereof.

The cleaner silencer structure includes an assembly of stamping arranged to provide a cleaner element 12 and a silencer element 13.

The cleaner element 12 comprises a casing 14 having a continuous side wall 16 and a bottom wall 17. The bottom wall 17 is formed to provide a closed upwardly extending or cupped central part 18 surrounded by a downwardly extending annular part 19. The space within the casing 14 is adapted to be iilled entirely with tiltering material 21 of any suitable type, the filtering material being adapted to extend entirely across the charnber formed by the casing 14 from within the side wall 16 and to entirely cover the bottom wall 17. In the present instance, the iilter element 21 of filtering ina-- 'ice terial has been pressed or molded to substantially lit the shape of the interior of the casing 14.

The annular part 19 of the wall 17 is adapted to be radially and circumferentially slotted in such manner that spacing members 22 may be bent downwardly from the annular part 19 to provide spaced and annularly disposed inlet openings such as that indicated at 23. The openings 23 provide the only air inlet means extending through the casing 14 for the admission of air to be cleaned by the filter element 21. Surrounding the lower part of the casing 14 is an inlet casing 24 which is formed by a continuous side wall 26 and a closed bottom wall 27. The side wall 26 may be uniformly spaced from the side wall 16 to provide an annular inlet passage 28 leading to the lower part of the cleaner casing 16 and to the inlet opening means 23. The lower wall 27 has an outwardly depressed annular part 29 and an upwardly and inwardly depressed central part 31. The part 31 is adapted to extend within but in spaced relation to the part 18 of the wall 17 of the cleaner casing 14. The outwardly depressed part 29 of the inlet casing 27 is spaced below the lower extremity of the spacing means or supports 22 and provides an oil chamber or sump indicated at 32. The oil chamber or sump 32 is adapted to be filled with oil during the operation of the device to the level indicated at 33.

The central part 31 of casing 24 extends upwardly within the wall 17 to a height exceeding the oil level 33.

yBetween the lower walls 17 and 2'/ is an oil control baille 34 for the cleaner 12. The bathe 34 may be formed to provide an upwardly depressed part 36 which may fit the exterior surface of the upwardly depressed part 18 of the wall 17. Beneath the inlet openings 23 the outer part of the baie 34 slopes downwardly towards the wall 26. The supports 22 are adapted to engage and to rest upon baie 34. The wall 26 is formed to include an annular bead or rib 37 engaged by the baffle 34 for supporting the baffle and for compressing the baffle against supports 22 and the outer surface of wall 18 against wall 17. Openings 35 are struck from batiie 34 about and near the peripheral edge thereof to provide passage means, through which the oil may circulate from the under to, the upper side of the baille during operation of the cleaner. ,a

Apertures 40 are also formed in baie 34 directly be-A neath the inner edge of openings 23 to enable the returnt flow of oil from filter 21 to pass under the bathe where` foreign material which may have been washed back` with the oil may be collected in sump 32. The inletcasing 26 may be held in position around the cleanercasing 14 by fastening means such as the bolt and wing nut device indicated at 38. The head of the bolt may engage the inner surface of the wall 16 and the bolt may extend through and be staked within aligned openings in the walls 17 and 27 and the baffle 34 so that when the wing nut is tightened the casings 14 and 24 will be drawn together and in so doing will compress the outer annular portion of baille 34 into rattle free engagement with wall 26 and spacers or supports 22, and the inverted cupped portion 36 of the batlie into sealing engagement with the` outer surface of part 18 of bottom wall 17 of the cleaner element.

It will be apparent that when the wing nut is removed the inlet casing 24 may be entirely removed from the casing 14 and the bathe 34 so that the casing may be cleaned and new oil may be supplied to fill the sump- 32.

The upper wall 39 of the cleaner 12, which is 'a cornmon wall separating the cleaner and silencer elements 12'and 13 respectively, may be generally arcuate'in formation to provide an outlet chamber 41 about 'the lilter element 21 and the casing 14. The space above wall 39 is enclosed by an inverted cupped annular wall indicated at 42 and a conical joining wall 45 which are" crimped .together-as at 46. The 'adiacenti-y engaged-edges of walls 16, 39 and 45 are anged as at 43 to provide means for securing the walls together. Between the peripheral flanges on the walls 39 and 16 it may Ybe con.- sidered desirable to provide ascreen 4:4 which extends over the filter element 31 for securing the iilter element within the casing 14.

y The wall 39 is formed. upwardly within the space within wall 42 to enlarge chamber 4,1. and to. accommo.date. a. tubeor conduit 49, disposed obliquely within silencer 13. The, `tube 49 extends through an outlet opening formed wall 39 to vprovide an outletl passageway from chamber 41 abovefthe cleaning element 21. A, tiange 48 secured to the tube 49 provides means for securing the tube within the outlet, opening of wall 3.9. The tube 4.9 extends from well within. chamber 41 into the cover 51 Qfl the Silencer element. and has. the outlet. end thereof diposedjwithiu `the cover- A tubular extension member 47 flared at its inner end as at 55 is telescoped within the inlet end of tube 49 to increase the length of the outl'et passage within chamber 41. Apertures, 65 may be formed within the wall of tube 4 9 at any position along its length to provide acoustical passages communicating with the chamber 66.

The upper end of the silencer 13:A may be formed by a closure, cap or end casing indicated at '1. The end casing 51 may be formed by an upper wall 52 and a lower wall 53, the upper wall being formed to provide a continuous "side wall 54 extending laterally toward the lower wall S3. A iiange 56 is provided around the peripheral edge of the lower wall 53 which is received within a bead 57 formed in wall 52 for securing the two walls rigidly together.

The end casing 51 may be elongated' in formation as is shown by FiguresV l and 2 and may be provided adjacent one end thereof with a relatively large opening surrounded by a ange 58 formed in the lower wall 53. The ange 58 is adapted to be disposed in telescopic relation to vthe upper end of the Wallv 42 so lthat the two may be rigidly' and permanently secured together to close the upper end of the silencer chamber. With such construction itl will be apparent that the end casing 5-1 has a partextending laterally from the upper end of the structure to provide an elongated and relatively Wide outlet which mayY be connected tothe induction. system of an engine or any other device.

The end' of the casingy 51 opposite'th'e ang'e 58 may be. flanged as indicated at 59 to. form an outlet passage 60.- and mayV be, slotted around the ange 59 as indicated at- 61. to provide means for connecting the structure to the.. induction passage of any device with which the structure; may be used. Attaching means such as that indicated at may'extend. around, the flange 5.9, for tightening the ange around. tbc induction means.

'Ehe Silencer 1.3 also. may be. provided with sound ab Sorbing meansr 71. which. may be secured against the inside surface of an obliquelydisposed part 72. of the. sider -wa-ll 5.4 of the casing 51. and immediately adjacent the. outlet passage 6i)v leading from the structure. '[he slope ot the. wall part 72 is made in such away as. to directA the air flowing through the` structure` downwardly into. the` outlet passage 6.0. The sound absorbing means 71. may be. Constructed. iu any suitable manner as byA providing a. fibrous body ofsound absorbing material 7,4. within.` a.: perforated wall 76 extending across the end of the casing- 5..4.. Thcwall. 76.1nay be provided with. flanged ends 77 which may be welded or otherwise. secured. to the wall'v 52. The sound absorbing material 74 maybe employedl to, absorb high pitch',` hissing sounds that, may. emanate. from. the, induction means. through the ontlet opening PlSSagc, 6 0. l' It will. be apparent that .the structurel() is largely formed from a relatively Small number of parts, securedl together in such a way as. to.. constitute. a single. unit; The only parts. which require. removal. in. order to service the structurels. the casngltt.

'casacca A unique structural arrangement is provided in this integral cleaner silencer with great simplicity to provide necessary resonance, inertance, acoustical capacitance, Iand impedance factors necessary to attenuate sound waves otherwise most disturbing.

The chamber 66 formed within walls 42 is a resonator `chamber of increased acoustical capacitance due to the igreater volume by having walls 42 of greater circumferential dimension than would result in providing a. straight cylindrical wall or sleeve between ange 5S 'of the silencer' cover 51 and the wall 16 of the. cleaner clement. The greatest acoustical impedance obtainable within the limited space available is provided by extending outlet tube 49 within cover 51 and by providingv the extension member 4.7 on the atmospheric side of the acoustical capacitance. The extension member is ared at its inlet end to provide less resistance to air ow through the tube 49. The extension member 47 also. pro- -vide's a longer sound path through the tube 49 Within the chamber 41 on the atmospheric side thereby providinggreater impedance for attenuating sounds on the atmospheric side whereV they may be heard. An inertance factor may be broadly said to be provided by the disposition of theoutlet end' of the tube 49 within cover l511 and close to the walls 52 and 53 thereof. The wall 152 and the ange 58 of wall 53- in combination with the outer surfacel of the tube 49 provide an annulus of some length and capacity which induces inertance The apertures `formed in tube 49: provide for the more rapid expansion of gases flowing through the tube and are tuned with chamber 66 to eliminate high frequency sounds.

The inertance and resonator characteristics are not provided to. attenuate all sounds` of low frequency noises but are sulcien-t in combination with the acoustical capacitance, and impedance to have. an elect upon low fre.- quency sounds. In addition, such factors are provided with n.0 appreciablef increase. of materiali. labor, or rearrangement ofstructural elements.

The, majorY asset4 of the proposed cleaner silencer is the provision of a simple acoustical capacitance. suicient, within the space provided, as dictated by its use. here withv automotive. engines, to obtain. suicient sound attenuation- Ordinarily acapacit-ance coupled to the sound path,Av here through cover 51 and tube 49; does not remove low frequency noises to a satisfactory level... However, where. higher frequency noises are more objectionable a more. satisfactory reduction. of noise over a desired range is, obtained: inY the use. of a simple acoustical capacitance as here provided in conjunction with the other features described.

We claim:

1. A cleaner silencer unit comprising a cleaner elcment and a silencer element having a common. wall and including an elongated conduit having opposite ends. extending through said comrnon wall and. substantially within said cleaner and within said silencer, a cover member closing` said silencer element,. the outlet end of said conduit being disposed within. said cover member, chamber means formed within said silencer by the. walls of saidv silencer and cover member about saidl conduit, to provide a resonator of predetermined acoustical capacitance for attenuating sounds ofV high frequency within. said cleaner silencer unit, and a plurality of apertures formed through the end of said. conduit for communication withY said chamber means..

2. The cleaner silencer unit of claim 1 including an extension member secured to the inlet end of said conduit within said cleaner unit for increasing the sound path through said conduit to provide greater acoustical impedance on the atmospheric side of said 'chamber means;

3.. A cleaner silencer-unit 'including a cleaner element and a silencer element formed withY a Vcommon separating walls, a. tubular member having opposite ends. extended. through said. common wall and substantially within said cleaner and said silencer elements to provide communica,

tion therebetween, chamber means formed by the walls of Said silencer element about the outlet end of said tubular member, air collecteing means provided about the inlet end of said tubular member Within said cleaner element, :said chamber means providing an acoustical capacitance for attenuating sounds of high frequency within said silencer element, said tubular member extending into said air collecting means sutiiciently to provide increased acoustical impedance with said tubular member on the atmospheric side of said silencer unit to assist in the attenuation of sounds otherwise audible within said cleaner element.

4. A cleaner silencer unit including cleaner and silencer elements having a common separating wall therebetween, a tubular member extended obliquely through said common wall within both said cleaner and said silencer elements, an acoustical chamber formed bythe walls of said silencer element about the outlet end of said tubular member within said silencer element, a plurality of spaced apertures formed through said tubular member near the outlet end thereof for communication with said acoustical chamber, and an extension member connected to the end of said tubular member within said cleaner element to provide increased acoustical impedance to attenuate sounds Within said cleaner silencer unit.

5. A cleaner silencer unit including cleaner and silencer elements having a common separating wall, a tubular member extended obliquely through said wall within both said cleaner and silencer elements for communication therebetween, a cover member closing ofi said silencer unit and including an outlet opening formed therein communicating with the outlet end of said tubular member, said outlet end of said tubular member being disposed in close spaced relation to the walls forming said cover to introduce an inertance thereabout, a resonator chamber of predetermined acoustical capacitance formed by the walls of said silencer element and cover member about the outlet end of said tubular member, and spaced apertures formed through said tubular member near the outlet end thereof for communication with said resonator chamber, the inlet end of said tubular member extended within said cleaner element providing acoustical impedance sufcient to attenuate sounds not attenuated within said resonator chamber.

6. A cleaner silencer unit comprising a cleaner ele ment and a silencer element having a common separating wall, said silencer element including chamber means formed by the walls thereof, said cleaner element including an air collecting chamber formed by the walls thereof within said chamber means of said silencer element, a conduit extended through said common wall within said chamber means and said air collecting chamber, a cover member secured over said silencer element and having an outlet passage formed therein in communication with the end of said conduit within said silencer element, a plurality of spaced apertures formed through said conduit near the outlet end thereof for communication with said chamber means, said chamber means providing a resonator chamber of predetermined acoustical capacitance for attenuating sounds of high frequency within said silencer, and said conduit extended within said air collecting chamber of said cleaner element providing acoustical impedance sufficient to attenuate audible sounds on the atmospheric side of said silencer within said cleaner element.

7. A cleaner silencer unit including a casing having cleaner and silencer elements formed therein, a common dividing wall formed within said casing for separating said elements, said dividing wall having an opening formed therein to provide communication between said elements, a tubular member secured within said opening and extending through said silencer element, a cover member secured over said silencer and including an outlet passage, a silencer chamber formed about said tubular member by the walls of said cover and said silencer element, the outlet end of said tubular member extending within the outlet passage of said cover member in close spaced relation to the walls thereof, and apertures formed through said tubular member for communication with said silencer chamber, said silencer chamber having a predetermined acoustical capacitance to provide a tuned resonator for attenuating high frequency sounds within said silencer.

8. A cleaner silencer unit including integrally formed cleaner and silencer elements having a common dividing wall, a cover element secured over `said silencer element and including an elongated outlet passage, an opening formed through said dividing wall, a conduit secured within said opening and extended through said silencer element to within close spaced relation ot the walls of said cover element forming said outlet passage, a silencer chamber formed by the Walls of said silencer and cover elements about said conduit, a plurality of spaced apertures formed through said conduit to provide communication with said silencer chamber for the attenuation of sounds transmitted through said conduit, and said silencer chamber communicating with said outlet passage about the outer end of said conduit between said conduit and said cover walls to provide an acoustical inertance like- Wise for the attenuation of disagreeable sounds.

References Cited inthe tile of this patent UNITED STATES PATENTS 2,243,083 Brown May 27, 1941 2,458,745 Sebok et al. Ian. 11, 1949 2,602,520 Dreznes July 8, 1952 

